Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

McGraw-Hill Technology EducationMcGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All

rights reserved.

Edited by: Edited by: Rahman Ali, Lecturer in Rahman Ali, Lecturer in Computer Science, QACC, Computer Science, QACC, University of PeshawarUniversity of Peshawar

Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

McGraw-Hill Technology Education

Chapter 1A

Introducing Computer Systems

Introducing Computer Systems

The Computer Definition“A computer is a device that accepts input, manipulates

it under a sequence of instructions (a program) and produces an output”.

“ It is a device that accept data (INPUT) , convert it into electronic pulses and signals, perform certain steps on the data under given instructions (PROCESSING) and generates desired results in human understandable form (OUTPUT)”.

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InputInput ProcessingProcessingInstructionsInstructions

OutputOutput

Data vs InformationData : “Any Combination of facts and figures in

their raw or unprocessed form .“ e.g. individual facts like first name, price,

quantity ordered ,Names of cities, digits, alphabets etc.

Information: “ It is a meaningful collection of data” OR “ Information is the raw data that has been manipulated

and organized in the form of results/outputs, up on which people can take necessary decisions”

e.g. A sorted list of names , a telephone bill , a record of student’s marks.

Data is processed by the computers to produce relevant information.

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Uses of computers

• Computers for individual uses

• Computers for organizations uses

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Computers For Individual Use

• Mostly computers are used by individual users. This means that they cannot be used by more than one users at a time.

• Some computers are shared (used) by multiple users at a time.

• NOTE:– These computers are called personal

computers– Also called microcomputers

Types of personal computers (PC)

• Desktop

• Workstation

• Notebook

• Laptop

• Tablet

• Handheld: Palmtop or pocket PC, PDA

• Smart phone: cell phone+PDA

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Desktop computer

• A desktop computer is a personal computer (PC) in a form intended for regular use at a single location.

• Early desktop computers are designed to lay flat on the desk, while modern towers stand upright.

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Workstations

• It is a type of computer used for: – engineering applications (CAD/CAM), – desktop publishing, – software development, and – other types of applications that require a

moderate amount of computing power and relatively high quality graphics capabilities.

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Workstations

• Most workstations are single-user computers. • The term workstation has also been used to

refer to a mainframe computer terminal.• In networking, workstation refers to any

computer connected to a local-area network. It could be a workstation or a personal computer.

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Desktop vs workstation

• Workstations offered higher performance than desktop computers, especially with respect to CPU and graphics, memory capacity and multitasking capability.

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Notebook computers• Notebook computers are:

– Small portable computers– Weighs between 3 and 8 pounds– About 8 ½ by 11 inches– Typically as powerful as a desktop– Also called laptop– Can include a docking station: to connect large

monitor, keyboard and mouse

Laptop • A small, portable computer -- small enough that it can

sit on your lap. Nowadays, laptop computers are more frequently called notebook computers.

• Similar in operation to desktops• Powerful than notebook• Laptop computers are miniaturized and optimized for

mobile use. • They are enabled with an inbuilt keyboard, touch pad

acting as a mouse and a

liquid crystal display.

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Tablet computers

• Tablet computers– Newest development

in portable computers

– Run specialized versions of office products

– They use the touch screen technology.

– Tablets come with an onscreen keyboard or use a stylus or a digital pen.

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• Handheld computers– Very small computers– Also called Palmtop or pocket PC– Personal Digital Assistants (PDA)– Note taking or contact management: phone

directory, agenda of the meetings– Data can synchronize with a desktop– Can connect to a wireless network for

Internet

Handheld computers

Handheld computers

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Smart phones

• Smart phones– Hybrid of cell phone and PDA– Web surfing, e-mail access

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Computers For Organizations

• Computers are not only used by individuals

• Some computers are used by more than one users at a time i.e. enterprises, schools, companies

• Thousands of users are attached

Types of Computers For Organizations

• Network servers

• Mainframe

• Minicomputers

• Microcomputers

• Supercomputers

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Network servers

• Network servers– Centralized computer– All other computers connect– Provides access to network resources– Multiple servers are called server farms or

cluster– Often simply a powerful desktop– Desktop, laptops, tablets and workstations

are attached either wired network or wireless

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Network servers

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Mainframes• Used in large organizations• Handle thousands of users• Users access through a

terminal:– Dump terminal:

• no processing no storage

– Intelligent terminal: • processing is there but no storage

– Standard PC:• Having both

• Mostly specialized for its tasks e.g. mainframe in State’s department of motor vehicle for storing drivers, drivers license etc. and nothing else.

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Minicomputers

• Minicomputers– First released in 1960’s– Called midrange computers– Power between mainframe and desktop– a minicomputer is a multiprocessing system

capable of supporting from up to 200 users simultaneously.

– Used in smaller organizations– Users access through a terminal

Minicomputers

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Supercomputers

• Supercomputers– The most powerful

computers made– Handle large and

complex calculations– Process trillions of

operations per second

– Found in research organizations, weather forecasting etc.

Supercomputers

• Other applications– Quantum physics, – mechanics, – molecular theory– Modeling complex processes like nuclear fission and fusion

reactions – Mapping human genome

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Supercomputers

1A-27 IBM Blue Gene P supercomputerIBM Blue Gene P supercomputer

Supercomputers

Titan: Fastest computer of the world1A-28

Supercomputers

• Titan, is the world’s fastest computer• Developed by US department of energy• Have a speed of 20000 trillion calculations

per second, equal to 20 petaflops/second• Before this, Tianhe-1A, was made by

China, in November 2010, which was the fastest supercomputer. The speed was 2.5 petaflops

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Computers In Society

• More impact than any other invention– Changed work and leisure activities– Used by all demographic groups

Computers In Society

• Computers are important because:– Provide information to users– Information is critical to our society– Managing information is difficult – Manage your schedule on daily and hourly basis– Manage a list of contact– Make notes on fly– Carry your data with you– Can work anywhere– Help the disables to work at home without leaving

their homes

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Computers In Society

• Computers at home– Many homes have multiple computers– Most American homes have Internet– Computers are used for

• Business• Entertainment• Communication• Education• Finance

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Computers In Society

• Computers in education– Computer literacy required at all levels

• Computers in small business– Makes businesses more profitable– Allows owners to manage– Can easily setup a business at home or a small

office– Using inexpensive computers and softwares for

promoting their businesses such as Quickbooks (accounting software) etc.

Computers In Society

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Quickbooks accounting software Quickbooks accounting software

Computers In Society

• Computers in industry– Computers are used to design products– Process control: Assembly lines are automated– Shipping

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Computers In Society

• Computers in government– Necessary to track data for population

• Police officers• Military • Tax calculation and collection

– Governments were the first computer users

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Computers In Society

• Computers in health care– Revolutionized health care– New treatments possible– Scheduling of patients has improved– Delivery of medicine is safer– Machines and devices for:

• Ultrasounds• X-Rays• MRI: Magnetic Resonance Imaging• Laser eye and kidney surgery

Computers In Society

• Computers in health care– Robotic surgical devices. Perform remote

surgery– Training surgeons using Virtual reality

technology

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Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.

McGraw-Hill Technology Education

Chapter 1A

End of ChapterEnd of Chapter